Use of Compost in Soilless Cultivation

Abstract

An experiment was performed with compost prepared from bark and sewage sludge to evaluate its suitability for amending growing media used in the soilless cultivation of cucumber (Cucumuis sativus), tomato (Lycopersicon esculentum), strawberry (Fragaria vesca) and Gerbera daisy (Gerbera jamesonii). Four media were compared: rock wool; white peat; a mixture of 40 percent white peat, 35 percent rice chaff and 25 percent compost by volume; and a mixture of 50 percent white peat and 50 percent compost by volume.Both of the growing media amended with compost offered clear advantages for all species tested: improved plant nutrition, better vegetative growth and an increase in both the quantitative and qualitative characteristics of production. The physical and physiochemical properties of compost combine with those of white peat to create growing media that offer higher production potential than can be obtained with pure rock wool or peat. Furthermore, the use of compost did not lead to dangerous increases in the content of heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in the fruit of the species tested.